This invention relates to a terminal for the armature of an electrical machine and more particularly to one that facilitates and simplifies the connection to coil winding ends.
As is well known, in rotating electrical machines the armature normally has a plurality of circumferentially spaced pole teeth around which electrical coils are wound. Regardless of whether the machine is a generator or a motor, it is necessary to provide a connection between the wire ends of the coils with each other in one or more phases and also to an external terminal to either deliver the generated electrical power, in the case of a generator, or to receive electrical power, in the case of a motor. This presents several difficulties and challenges to automated manufacture.
For example published Japanese Patent Application, publication number Hei 6-233483 shows a construction in which a wire connection base board (terminal wiring unit) is positioned at an axial end of the armature. The wire ends of the coils (both the winding head and winding tail) for each phase of the armature is connected to a respective terminal of the terminal wiring unit. The wire connection unit disclosed therein is made up of a unit main body; first, second and third phase-specific terminal members (conductive members) corresponding to respective phases of the stator, such as a U-phase, a V-phase and a W-phase; a common conductive member; and plural insulators for insulating these conductive members.
The phase-specific terminal members (conductive members) are of the same shape as each other. That is each has a member body (main body) generally of a C-shape made of a conductive material such as a copper sheet provided integrally with plural projections at its outer peripheral edge. The lower part of each projection is provided integrally with a securing portion generally of a U-shape. The phase-specific terminal members are spaced from each other in the axial direction relative to the unit main body. The wire ends of the coils extending from the armature are connected by soldering to the securing portions of the phase-specific terminal members when so assembled.
Obviously, the work of interconnecting the wire connection unit and the coil ends is labor intensive, since the worker has to draw out wire ends from the coils of the stator, engage them with the securing portions, and carry out soldering while maintaining them in the securing portions In addition, since the phase-specific terminal members are embedded in an insulating material when so placed, the axial positions of the terminals are different for respective phases so that the work of joining with solder is cumbersome and time consuming.
Therefore it may be thought to use a fusing method for joining, by placing the wire end in a terminal of a U- or V-shaped section and fuse and join the elements while crimping the terminal. In such a fusing method, the objects to be joined together are placed between an electrode bar and an electrode receiver, heated while being pressed with the electrode bar, and joined together by fusing one or both of the objects to be joined together. Since this method requires no intervening matter such as solder and has the possibility of automation, considerable advantage can be obtained in cost and product improvement in comparison with the conventional wire connection by soldering.
However, when the wire end is simply placed in a terminal of a U- or V-shaped section, for crimping the terminal with an electrode bar and fusing, the wire end occasionally slips off at the time of fusing because of the shape of the section of the terminal, causing poor reliability in joining the wire end to the terminal.
Therefore it is a principal object of the invention to provide an improved terminal construction in which displacement of the wiring ends during attachment is prevented.